Background and Aim: Cigarette smoking is strongly associated with coronary artery disease and atherosclerosis, both of which are influenced by endothelial dysfunction. Antioxidant therapy has the potential to inhibit the pathogenesis of atherosclerosis. purpose of the study was to assess the antioxidant potential of β-hydroxybutyrate by examining its effects on eNOS levels and VCAM-1 expression in male Wistar rats exposed to cigarette smoke. Material and methods:. There were 25 Wistar rats involved in this study under a laboratory experiment, which were distributed into five experimental groups. Two control groups were included, with one group receiving no intervention (K-) and the other group exposed to daily exposure to 40 cigarette smoke (K+). The remaining three groups received daily doses of β-hydroxybutyrate-(R)-1,3-butanediol monoester supplement (DeltaG; KE) at 1.5g/kg/day (P1), 3g/kg/day (P2), and 6g/kg/day (P3), respectively, in addition to daily exposure to 40 cigarette smoke. After a 28-day exposure period, eNOS levels and VCAM-1 expression in the aortic tissue were measured. The data were analyzed using the ANOVA test, followed by Fisher’s LSD post hoc test. Results: The administration of β-hydroxybutyrate led to a significant increase in eNOS levels in the Wistar rat aorta (p = 0.036; p<0.05). However, there were no huge contrasts seen in VCAM-1 expression (p = 0.426; p>0.05). Conclusion: This study demonstrated that while Wistar rats exposed to cigarette smoke for 28 days experienced an increase in eNOS levels, there was no decrease in VCAM-1 expression.These findings suggest the potential of β-hydroxybutyrate as a vasodilator in mitigating the effects of cigarette-induced endothelial dysfunction.